Sony Corporation

Hisaki Hiraiwa

Takehiro Sugita

Takashi Usui

Shigeru Sugaya

Mitsuhiro Suzuki

Shinichi Kuroda

Hideaki Sato

Takushi Kunihiro

Hidemasa Yoshida

Norio Shimo

Takuji Maekawa

Eiichi Osawa

Erika Tanimoto

Sei Suzuki

A wireless transmission method is provided in which a wireless network is constructed by a plurality of wireless transmission apparatus, a predetermined wireless transmission band is reserved and data is transmitted by radio. According to the wireless transmission method an allowable transmission error rate can be anticipated, whereby information transmission based on the unnecessary reservation of a wireless transmission band can be removed. In a wireless transmission method in which a wireless network is constructed by a plurality of wireless transmission apparatus, a predetermined wireless transmission band is reserved and data is transmitted by radio, a desired quality in a wireless transmission is selected by an arbitrary wireless transmission apparatus of a plurality of wireless transmission apparatus and a necessary wireless transmission band is reserved.

Wireless transmission method and wireless transmission apparatus

A packet passed to an IEEE 1394 bus is received by a packet receiver ( ) and stored into a packet buffer ( ). Source and destination IDs from the packet buffer ( ) are supplied to a comparison/calculation circuit ( ) which are also supplied with ID values from a subnetwork routing register ( ), bus routing register ( ) and node IDs register ( ). The comparison/calculation circuit ( ) will judge, based on such signals, whether the packet is to be transferred, and when it decides that the packet is to be transferred, will activate the output signal and open a gate ( ) to transmit the packet to an inner fabric ( ).

Network system

A wireless transmitting method capable of simplifying a transmission packet. In which error correction codes C to C added to data information (FIG. A) sent from various equipments connected through a high-speed serial bus are removed to convert the data information into data information (FIG. B) in a predetermined wireless environment, and error correction codes C to C are added to the data information (FIG. B) in the predetermined wireless environment thus converted as shown in FIG. C for transmitting by wireless as shown in FIG. D.

Wireless transmitting method, wire transmitting method, wireless transmitter and wired transmitter

A radio communication system is formed of a plurality of radio communication terminals and a radio communication control terminal for controlling radio communication. Data communication is performed between each radio communication terminal and the radio communication control terminal by the orthogonal frequency division multiplexing (OFDM) method. Data is multiplexed with a frame structure having the specified number of symbols by the TDMA method. The radio communication control terminal transmits a synchronization acquisition code to the plurality of radio communication terminals in each frame. Each radio communication terminal receives the synchronization acquisition code, sets a timer according to the receiving timing of the synchronization acquisition code, and sets the transmission timing and the receiving timing with the timer being used as the reference. With the use of the OFDM method, demodulation is performed without an error even if jitter occurs. Since the timing of transmission and receiving is set with an M sequence at the top of a frame being used as a reference, the timer of each radio communication terminal is set to the same time. With the use of this time information, only necessary symbols in a frame are demodulated to reproduce the data at receiving.

Radio communication system

The present invention provides an information processing apparatus, system and method and a providing medium which allow establishment of isochronism in isochronous transactions between different environments. The information processing system includes a bridge for bridging a wire environment and a radio environment. The bridge includes a comparator which compares the count value of a cycle time register for the wire environment and the count value of another cycle time register for the radio environment with each other and outputs an error value between the count values as a cycle report packet to a node which acts as a cycle master in the radio environment. The node receives the cycle report packet transmitted thereto from the bridge and corrects the count value of a cycle time register thereof in response to contents of the cycle report packet. Then, the node transmits a frame synchronization packet to the other nodes in the radio environment at a timing in accordance with the corrected count value of the cycle time register. Each of the nodes resets the value of its an own built-in cycle time register in response to the frame synchronization packet transmitted thereto from the cycle master node.

Method and apparatus for interfacing isochronous communication systems

A radio communication system where data is transferred by TDMA in one frame. A frame is formed of a control-data transfer time region and an information-data transfer time region. In the control-data transfer time region, polling is performed for each terminal and a transfer rate and whether transfer data exists are returned to a control station as an ACK. The control station assigns a channel to each terminal according to this information a time period for data transfer in the information-data transfer time region is assigned to each terminal which has made a transmission request. In the region, asynchronous data and isochronous data can be transferred together. Since data is transferred in the time period assigned in advance in a frame, a constant transfer rate is obtained without being affected by an increase or decrease of traffic.

Radio communication system, transmitting apparatus, radio communication control apparatus, receiving apparatus, and radio communication method

A correlation detecting apparatus is capable of securely detecting a M sequence code forming a reference for timing even when a plurality of signals with different amplitudes are time division multiplexed includes matched filter ( ) for detecting a predetermined code from a received signal, an average amplitude detector circuit ( ) for detecting an average amplitude of the received signal, and a divider circuit ( ) for normalizing an output of the matched filter ( ) by an output of the average amplitude detector circuit 83 are provided. The output of the matched filter ( ) normalized by the divider circuit ( ) is compared with a threshold value for outputting a correlation detecting signal. When a received signal level is large, the output level of the matched filter ( ) becomes large. However, in this case because the average amplitude of the received signal also becomes large, a divided value of the output level of the matched filter ( ) by the output level of the average amplitude detector circuit ( ) makes almost no change. In contrast to this, the output level of the matched filter when an M sequence is received remains nearly constant irrespective of an input signal level. Therefore, the received signal of M sequence can be detected without fail from the output of the comparator circuit ( ).

Correlation detecting apparatus, its detecting method and communication apparatus and its communication method

A time division multiplex transmitting/receiving system converts a signal to be transmitted into a signal having a predetermined frequency in a predetermined time slot, which is transmitted as a transmission signal, and receives a transmitted signal having a frequency different from the frequency of the transmitted signal at another time slot different from the time slot of the predetermined frequency, and for demodulating this received signal. The time division multiplex transmitting/receiving system includes a fixed oscillator, a variable oscillator, a mixer, a modulator, a converter, a frequency divider, and a demodulator. The fixed oscillator outputs a first signal having a constant frequency. The variable oscillator outputs a second signal having a predetermined frequency within a predetermined band range. The mixer mixes the first signal with the second signal. The modulator directly modulates a signal to be transmitted by employing the mixed signal. The converter converts the received signal into the intermediate signal by employing the mixed signal. The frequency divider frequency-divides the first signal outputted from the fixed oscillator. The demodulator demodulates the intermediate frequency signal outputted from the converter with using the output from the frequency divider.

Time division multiplex transmitting/receiving system

The present invention relates to an equalizing system in which an input signal is supplied to a series circuit of a plurality of delay means, the input signal and delayed output signals of the respective delay means are multiplied with coefficients and multiplied outputs are added to thereby produce an equalized output signal. In this equalizing system, the input signal is supplied to the series circuit of the plurality of delay means so that the input signal is transmitted in the positive direction within the series circuit so as to be sequentially delayed, the input signal is then transmitted in the reverse direction within the series circuit so as to be sequentially delayed, the input signal is transmitted again in the positive direction within the series circuit so as to be sequentially delayed, an amplitude error of the output equalized signal is detected, and coefficients multiplied with the delayed output signals of the respective delay means are calculated in response to the detected amplitude error so that the amplitude error is minimized.

Method for equalizing received burst signal

A digital demodulating apparatus which is high in accuracy in operation and simple in construction. The digital demodulating apparatus comprises an analog to digital converter for converting an input modulated signal having a carrier frequency of fc and a band width of 2B into a digital signal with a sampling clock signal of a sampling frequency of fs, a sampling clock generating circuit for generating a clock signal of the sampling frequency fs which is defined as

Apparatus for digitally demodulating a narrow band modulated signal

There is provided a system in which a transponder is carried by each vehicle traveling on or above the earth's surface which transmits a signal which is responsive to an interrogation signal to a ground station through two or more satellites and in the ground station, the position of the vehicle is determined from the propagation time differences of the response signals received via the satellites. In this system, the information indicative of the time lag which is required for the transponder to receive the interrogation signal and to transmit the response signal responsive to the interrogation signal is included in the response signal and then such response signal is transmitted. Thus, the time lag which is peculiar to each transponder and corresponds to the time required from the reception of the interrogation signal to the transmission of the response signal can be corrected. With this system, the positioning accuracy of each vehicle can be improved.

Method and apparatus for determining the position of a vehicle

The invention relates to a Viterbi decoder for decoding a convolutional code. Branch metrics are normalized, state metrics are calculated from the normalized branch metrics, and the synchronization and asynchronization are determined on the basis of the degree of increase in the calculated state metrics. Thus, the original data can be certainly decoded by a simple hardware without being influenced by the S/N ratio of the communication path.

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Kanagawa, Japan

Hisaki Hiraiwa